1. Field of the Invention
The invention lies in the computer technology field and, more specifically, in the personal computer technology. The present invention relates to a removable non-volatile memory device, that is, to a removable hard drive assembly and to various attendant methods of initializing such a hard drive, and to operating a removable hard drive.
2. Description of the Related Art
There exists an increasing need for the easy transportation of large amounts of computer programs and data. Frequently, data needs to be moved from one computer to another in a business situation or between an employee's business computer and home computer. At times data needs to be duplicated to prevent data loss. Data may need to be copied and stored in a separate physical location to allow disaster recovery. Because of the amount of data to be transported, a device is needed to allow quick data storage and recovery while being physically small for convenient transportation. Numerous devices exist that allow computer programs and data to be stored and physically removed from a computer system. All of them suffer from different limitations.
The far and away most successful of the prior art removable devices is the so-called floppy disk. It consists of a plastic disk that is covered with a magnetic material and is enclosed in a protective case. The disk is inserted into a drive within the computer which consists of magnetic heads, motors, servo positioners, and necessary electronics. The amount of data that can be stored on a 3½ inch disk is limited to 1.44 megabytes. The amount of data per disk cannot be significantly increased beyond 1.44 megabytes. While 1.44 MB was considered a large amount of data during the 1980s and the early 1990s, it is nowadays considered a very small amount. Furthermore, the data transfer rate is very slow. The drive contains mechanical components which are only partly isolated from dust. The magnetic heads used to record and recover data are susceptible to collecting dirt which renders the disks unreliable. For this reason and other mechanical considerations, the disks produced are frequently incompatible between systems.
In an attempt to increase the amount of data stored in removable media, several developments led to higher data density versions of the floppy disk. For example, a disk sold by SyQuest could store 1.5 gigabytes. However, the mechanical reliability of that medium was poor. The currently available versions have a capacity of between 100 and 750 megabytes. This amount of data is much larger than that of a floppy disk. However, it is still generally inadequate for most storage requirements. The amount of data that can be stored with that technology cannot be significantly increased. The devices are subject to the same limitations as the floppy disk drives. In addition, in order to remove the disk from the drive, the computer must be powered on and the computer's software must be working properly. There is a mechanical provision for removing disks when the computer system is not powered on; however, it is not reliable.
Computer programs and data can be stored on magnetic tape; however, this is not widely used because of low data transfer rates and poor reliability. In addition, the amount of data storage is limited and it is very difficult to access any particular part of the data since the tape must be physically positioned at that data location.
CD-ROM drives have a capacity of about 700 megabytes and DVD-ROM drives have a capacity of up to 9.4 gigabytes. While the capacity of DVD-ROM drives is adequate for many applications, the storage of data (“burning”) is somewhat slow and requires significant human intervention to set up the recording process. This is particularly difficult for large transfers because data must be distributed over a number of disks. Additionally, since the drives have exposed mechanical components and the medium is subject to dust and dirt, the reliability of the stored data can be compromised. It is impossible to remove the disk from the drive unless the computer is powered on and working properly.
With the continued reduction in the pricing of electronic memory devices, such as PROMs, EEPROMs and the like, many different such storage devices have recently been introduced. These electronically programmable devices are the only ones that do not use mechanical systems to record and recover data from the memory device. The capacity of such flash memory, also known as “Pen Drives,” for example, is currently limited to 1 Gigabyte. The media cost is still very high. Additionally, there are mechanical incompatibilities with a number of computer systems. To store a large amount of data, data files must be distributed over a number of devices, a time-consuming and error-prone process.